Although the structures of light emitting diodes (LED's) and the manufacturing processes for making those structures have matured through the years, there remain technical and economic challenges to the industry. Because of the high costs of substrates and growth processes, it is essential to the success of the manufacturing processes, that the footprint of each device be kept as small as possible that is consistent with the target light output requirements.
A particular challenge to reduction of the footprint exists in the case of LED's which employ insulating substrates and metal contacts which are situated on the same side of the substrate. In such structures, there is a tendency for current flowing between the metal contacts to concentrate in a small, lower impedance, preferred path through the light emitting surface. Consequently, much of the light emitting surface is not activated. To date this problem has been addressed by the provision of conductive, semi-transparent, window contact layers and by maintaining physical lateral separation of the contacts. Such separation seriously limits the number of devices that can be constructed on a substrate of any given size; and thus is an economic burden to the manufacturer.